The invention is based on a device for time-dependent control of the duration of regeneration of an air dryer.
Such a device is already known (German Patent Disclosure DE 195 23 219 A1, the priority application for International Application PCT/DE 96/00561, in which the spring is received by the end toward the cap on a spring plate and the spring plate is supported on an adjusting screw which coaxially passes through the cap of the cylinder. The spring plate and the adjusting screw make the known device more expensive. Moreover, moisture can penetrate the cylinder along the adjusting screw and lead to corrosion of the spring and disruption of the functioning of the device.